1. Field of the Invention
This invention relates to a semiconductor device and a manufacturing method thereof and is applied to an MIM (metal insulator metal) capacitor structure using a multilayer interconnection and a manufacturing method thereof, for example.
2. Description of the Related Art
Recently, it is more strongly required to develop a capacitor having large capacitance and stably operated under high frequencies in the field of an MIM capacitor (refer to Jpn. Pat. Appln. KOKAI Publication No. 2002-319625) utilizing a multilayer interconnection which is one of applications of an LSI (Large Scale Integrated) circuit as the higher performance of the LSI is required.
The capacitance characteristic of the MIM capacitor is determined by the area of the capacitor electrode (workability of the capacitor electrode) and the film thickness, thickness uniformity and dielectric constant (capacitance) of the capacitor insulating film. Therefore, in order to realize the large capacitance, it is necessary to enlarge the area of the capacitor electrode or reduce the film thickness, make the film thickness uniform and enhance the dielectric constant of the capacitor insulating film.
However, since it is also simultaneously required to reduce the dimensions determined by the LSI design, expansion of the area of the capacitor electrode has a limitation and it is extremely difficult to attain a desired capacitor electrode at present.
It is required to reduce the film thickness, make the film thickness uniform and enhance the dielectric constant of the capacitor insulating film. The conventional capacitor insulating film is formed by use of a film formation method such as a thermal oxidation method, sputtering method, CVD (Chemical Vapor Deposition) method, for example. Therefore, it is difficult to reduce the film thickness, make the film thickness uniform and enhance the dielectric constant of the capacitor insulating film. Particularly, for example, when the sputtering method or CVD method is used, the film thickness varies in the extremely thin film region of 10 nm or less and it is extremely difficult to form a film with uniform thickness.